(J, —1 A .

Details of Triangle Closures.

Mr. W. G. Nelson, who took charge of the field-work as from Ist March, 1939, reports as follows : — " Reconnaissance was commenced in Canterbury Plain area during March. It was found impossible to cover this area with figures possessing required strength unless use were made of high towers. " In order to meet this difficulty it is intended to establish stations on two water-towers each 120 ft. in height and to purchase two ' Bilby Towers ' for the purpose of elevating observer and his instrument, also lamp, above the level of the plains. As these steel towers are comparatively light, and may be erected, dismantled, and re-erected on various sites rapidly, it is considered that the initial cost will be more than recouped by the saving in cost of materials for and erection of the old-type wooden towers. Further, New Zealand timbers are hardly suitable for use in construction of high towers, and American timber, which is costly, would require to be used in the absence of steel towers. " It is proposed to make use of small hydrogen-filled balloons as an aid to reconnaissance on plains." HEAD OFFICE, DRAUGHTING BRANCH. (R. G. Dick, Assistant Surveyor-General.) Map Publication. —The following tables summarize the map publications and sale credits in district and head offices.

Table 1a. —Summary of Printing-costs of Map Publications for the Year ended 31st March, 1939.

TABLE 1b. —Summary of Map Sales and Credits for the Year ended 31st March, 1939.

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, T , Seconds. Number Averag0 m • l Closure. inangies. 0-0 to 0-5. 0-5 to 1-0. 1-0 to 1-5. 1-5 to 2-0. 2-0 to 2-5. 2-5 to 3-0. j 3-0 to 3-5. 3-5 to 4-0. Maximum. Seconds. Seconds. Geodetic .. 37 0-803 11 16 6 2 2 .. .. .. 2-210 Base net 26 1-123 8 6 5 4 1 1 .. 1 3-539 Subsidiary.. 60 0-976 17 21 12 5 1 2 2 3-189

Class of Map. Number of | Number of Total Cost . Average Cost Average Cost r Issues. j Maps printed. per Issue. per Map. £ s. d. £ s. d. s. d. Survey districts, 40 ch. .. 23 1,271 190 0 0 8 5 6 3 0 Survey districts, 80 ch. .. 30 7,500 230 3 8 7 13 6 0 8 Counties .. .. .. 3 1,200 146 12 10 48 14 7 2 6 Boroughs .. .. .. 1 450 34 11 0 34 11 0 1 6 Territorial and 4-mile .. 9 4,600 215 0 9 23 17 9 1 0 Miscellaneous .. .. 9 3,975 293 6 5 32 11 9 1 6 Totals .. .. 76 18,996 1,109 14 8

Item. Credits. £ s. d. £ s. d. Sale of lithographs to the public .. .. .. 1,710 9 9 Sale of lithographs to other Departments .. .. 850 2 4 Lithographs issued free to other Departments .. 775 14 9 Lithographs for office use .. .. .. 935 0 4 4,271 7 2 Sale of publications and plan forms .. .. 387 12 9 Search fees . . .. .. .. .. 13 15 0 Royalty fees .. .. .. .. .. 487 14 6 Total .. .. .. .. .. 5,160 9 5